Management computer and method of managing data storage apparatus

ABSTRACT

In a computer system having hierarchically-arranged data storage apparatuses, a management computer provides information required for performing operation on the data storage apparatuses. Through a network for collecting management information, storage area information and hierarchy information are collected from each data storage apparatus. Management relation information is created using the collected storage area information and the collected hierarchy information together with programs for respectively managing the data storage apparatuses, and, the created management relation information is held. Based on the created management relation information, a display screen expressing the hierarchy of the data storage apparatuses is created. Further, responding to operation by a user, a return considering the hierarchy is displayed.

This application is a continuation application of U.S. application Ser.No. 10/811,868, filed Mar. 30, 2004, the entirety of which isincorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates to a technique of managing a plurality ofdata storage apparatuses in a computer system including a plurality ofdata storage apparatuses, and in particular to a technique of managingdata storage apparatuses in a computer system in which those datastorage apparatuses are connected hierarchically.

A storage area network, i.e., a network for data storage apparatuses, inwhich a plurality of data storage apparatuses and a plurality ofcomputers are connected through devices such as switches and hubs, isbecoming popular. In a storage area network, a network of fibre channelsis mainly used as a network connecting data storage apparatuses andcomputers, and a computer and a data storage apparatus send and receiveSCSI (Small Computer System Interface) command blocks on a fibrechannel, to send and receive data and programs used by the computer ordata generated by the computer.

On the other hand, management of a configuration of data storageapparatuses and computers and monitoring of occurrence of a failure areperformed by sending and receiving SNMP (Simple Network ManagementProtocol) or CIM/WBEM (Common Information Model/Web-Based EnterpriseManagement) through IP network constructed separately from the abovenetwork of the fibre channels. This network is called a managementnetwork.

Thus, management and operation of a computer system comprising aplurality of data storage apparatuses, a plurality of computers and aplurality of switches and hubs are performed by constructing twonetworks, i.e., a storage area network and a management network (See,for example, Patent Document 1: Japanese Patent Laid-Open PublicationNo. 2002-288055).

On the other hand, there is a system in which a first data storageapparatus and a second data storage apparatus are hierarchicallyconnected to a computer (See, for example, Patent Document 2: PublishedJapanese Translation No. 10-508967 of International Application). PatentDocument 2 discloses a storage system that realizes online datamigration between the hierarchically-connected first data storageapparatus and the second data storage apparatus while the computer isnot aware of the hierarchy of the data storage apparatuses.

In a computer system having a plurality of hierarchically-connected datastorage apparatuses, it is not necessary for the computer to be aware ofthe hierarchy of the data storage apparatuses, when data storageapparatuses is sending/receiving the data to/from the computer, asdisclosed in Patent Document 2.

However, in the case of performing operation such as deletion of astorage area provided by a data storage apparatus to the computer, anadministrator should be aware of the configuration of the data storageapparatuses. This is because, for example, when the administratordeletes a storage area of a lower data storage apparatus withoutconsidering the hierarchy, a storage area used by an upper data storageapparatus is deleted also. When the administrator performs incorrectoperation on a storage area without considering the hierarchy of thedata storage apparatuses, it is possible to lose data held in thestorage area. Thus, in a computer system including data storageapparatuses, it is unavoidable to employ a technique of preventing suchincorrect operation.

SUMMARY OF THE INVENTION

As described above, the technique disclosed in Patent Document 2 aims tomigrate data from the first data storage apparatus to the second datastorage apparatus. On the other hand, Patent Document 2 does notdescribe configuration management of the data storage apparatuses havingthe hierarchical configuration of the two data storage apparatuses,i.e., the first data storage apparatus and the second data storageapparatus. In other words, Patent Document 2 does not refer tomanagement of the hierarchical data storage apparatuses considering thehierarchy.

The present invention has been made considering the above point. And, anobject of the present invention is to provide a management computer thatgives information required for operation on a data storage apparatus ina computer system having a hierarchical configuration of data storageapparatuses.

To achieve the above object, the management computer according to thepresent invention provides information, based on which, it is possibleto manage data storage apparatuses considering the hierarchicalconfiguration of the data storage apparatuses.

Namely, the management computer according to the present invention isconnected through a second network to data storage apparatuses that areconnected to computers through a first network. The above-mentionedmanagement computer comprises: a storage area information collectingmodule which collects respective pieces of storage area information fromthe data storage apparatuses connected through the second network,wherein each piece of storage area information relates to storage areasprovided by a data storage apparatus concerned; a hierarchy informationcollecting module which collects respective pieces of hierarchyinformation from the data storage apparatuses connected through thesecond network, wherein each piece of hierarchy information indicateshierarchy among data storage apparatuses held by a data storageapparatus concerned; and a management relation information creationmodule which sets hierarchy among the data storage apparatuses to createmanagement relation information, based on the pieces of storage areainformation and the pieces of hierarchy information collected in thestorage area information collecting module and the hierarchy informationcollecting module.

According to the present invention, in a computer system havinghierarchically-arranged data storage apparatuses, the managementcomputer can provide information required for performing operation onthe data storage apparatuses.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram for explaining an outline of a first embodiment ofthe present invention;

FIG. 2 is a system configuration diagram of the first embodiment;

FIG. 3 is a diagram showing an example of programs and data held in amemory 223 of a data storage apparatus 201 of the first embodiment;

FIG. 4A is a diagram showing an example of programs and data held in amemory 123 of a data storage apparatus 101 of the first embodiment;

FIG. 4B is a diagram showing an example of programs and data held in amemory 173 of a data storage apparatus 102 of the first embodiment;

FIG. 5 is a diagram showing an example of programs and data held in amemory 513 of a management computer 501 of the first embodiment;

FIG. 6 is a diagram showing an example of identifier format information650 used in first and second embodiments;

FIG. 7A is a diagram showing an example of storage area information 248in the first and second embodiments;

FIG. 7B is a diagram showing an example of storage area information 148in the first and second embodiments;

FIG. 7C is a diagram showing an example of storage area information 198in the first and second embodiments;

FIG. 8 is a diagram showing an example of hierarchy information in thefirst and second embodiments;

FIG. 9 is a diagram showing an example of management relationinformation in the first embodiment;

FIG. 10 is a flowchart showing processing of the management computer ofthe first embodiment;

FIG. 11 shows a screen image in the first and second embodiments;

FIG. 12 shows a screen image in the first and second embodiments;

FIG. 13 is a diagram showing an example of status change notificationinformation in the first and second embodiments;

FIG. 14 is a flowchart showing processing of notification from a datastorage apparatus of the first and second embodiments;

FIG. 15 is a system configuration diagram of the second embodiment;

FIG. 16 is a diagram showing an example of programs and data held in amemory of a management computer of the second embodiment;

FIG. 17 is a diagram showing an example of programs and data held in amemory 223 of a data storage apparatus 201 of the second embodiment;

FIG. 18A is a diagram showing an example of programs and data held in amemory 123 of a data storage apparatus 101 of the second embodiment;

FIG. 18B is a diagram showing an example of programs and data held in amemory 173 of a data storage apparatus 102 of the second embodiment;

FIG. 19A is a diagram showing an example of management computeridentification information 243 in the second embodiment;

FIG. 19B is a diagram showing an example of management computeridentification information 143 in the second embodiment;

FIG. 19C is a diagram showing an example of management computeridentification information 193 in the second embodiment;

FIG. 19D is a diagram showing another example of the management computeridentification information 243 in the second embodiment;

FIG. 20 is a flowchart showing processing of the management computer ofthe second embodiment; and

FIG. 21 is a diagram showing an example of management relationinformation in the second embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[First Embodiment]

<Outline>

For managing a computer system having a hierarchical configuration ofdata storage apparatuses, it is necessary in a management computer toprovide management utility software and a hierarchical configuration ina management screen, according to the hierarchical configuration of thedata storage apparatuses, in order to notify an administrator (who isgoing to perform operation affecting a plurality of hierarchy levels)that the operation affects a plurality of hierarchy levels, and in orderto make the administrator recognize the configuration of the whole datastorage apparatuses, understand the hierarchy level of the data storageapparatus as the object of the operation, and be aware of effect on thedata storage apparatuses of the other hierarchy levels. Further, whenthere occurs a change in the status of the data storage apparatuses, itis also necessary to present the change together with hierarchyinformation to the administrator.

Here, “a hierarchical configuration of data storage apparatuses” meansthat a plurality of data storage apparatuses are connected to a computerin a multistage way, seen from the computer.

A configuration for realizing the above-described functions in amanagement apparatus will be described below. First, referring to FIG.1, an outline of an embodiment of the present invention will bedescribed.

As shown in the figure, a computer system of the present embodimentincludes hierarchical groups of data storage apparatuses. As an example,the figure illustrates four computers 301 to 304, one data storageapparatus 201 constituting a first level, and two data storageapparatuses 101 and 102 constituting a second level.

Here, the data storage apparatus constituting the first level is onehaving only storage areas that can be directly recognized by a computer,and the data storage apparatuses constituting the second level are oneshaving a storage area that can be recognized by a computer through thedata storage apparatus constituting the first level. Hereinafter,“upper” in hierarchy of data storage apparatuses means a level on thecloser side to a computer, and “lower” means a level on the farther sidefrom a computer.

The computer 301 can recognize a storage area 211 provided by the datastorage apparatus 201, and the storage area 211 provided by the datastorage apparatus 201 responds to data read and write requests from thecomputer 301. The storage area 211 holds programs used by the computer301 and data used or generated by those programs.

Similarly, the computer 302 can recognize a storage area 212 provided bythe data storage apparatus 201, and the storage area 212 responds todata read and write requests from the computer 302. Further, through thedata storage apparatus 201, the computer 302 can recognize a storagearea 111 provided by the data storage apparatus 101. And, through thedata storage apparatus 201, the storage area 111 responds to data readrequests and data write request sent from the computer 302. Both thestorage areas 212 and 111 hold data.

The computer 303 can recognize a storage area 213 provided by the datastorage apparatus 201, and the storage area 213 responds to data readand write requests from the computer 303. Further, through the datastorage apparatus 201, the computer 303 can recognize a storage area 161provided by the data storage apparatus 102. And, through the datastorage apparatus 201, the storage area 161 responds to data read andwrite requests from the computer 303. In the present embodiment, thestorage area 213 can not hold data, and, as a matter of fact, thestorage area 161 holds data.

The computer 304 can recognize a storage area 162 provided by the datastorage apparatus 102, and the storage area 162 responds to data readand write requests from the computer 304. The storage area 162 holdsprograms used by the computer 304 and data used or generated by thoseprograms.

In the computer system shown in FIG. 1, the data storage apparatuses101, 102 and 201 have respective management interfaces 120, 170 and 220.The data storage apparatuses 101, 102 and 201 are connected to amanagement computer 501 through the management interfaces 120, 170 and220, respectively.

The management computer 501 is provided with management programs 521 to523 for managing the data storage apparatuses connected to themanagement computer 501. The management programs 521, 522 and 523 areprograms for managing the data storage apparatuses 201, 101 and 102,respectively.

Further, the management computer 501 is provided with a choosing program525. The choosing program 525 is a program for choosing from themanagement programs 521 to 523, and for generating a display screenimages according to information on the hierarchy of the data storageapparatuses.

The management computer 501 is connected to a management console 601.The management console 601 is provided with a display unit 610. And, onthe display unit 610, the management computer 501 can display screenimages outputted by the management programs 521-523 of the managementcomputer and screen images outputted by the choosing program 525.

The display unit 610 has two windows, i.e., a display area 615 fordisplaying a screen image of a management program, and a display area611 for displaying a screen image of the choosing program 525. Thus, thedisplay unit 610 can present information required for managing the datastorage apparatuses and a configuration for understanding the hierarchyat the same time to the administrator.

The choosing program 525 is a program for acquiring hierarchyinformation 245 showing a hierarchy status of the data storageapparatuses as shown in FIG. 2, to make up a screen image 620 accordingto the acquired hierarchy information 245.

In the case of an example of the hierarchy information 245 shown in FIG.8, a data storage apparatus “ABC.XX200.0123” (the data storage apparatus201 in the figures) is connected with a data storage apparatus“DEF.YY100.0456” (the data storage apparatus 101 in the figures) and adata storage apparatus “GHI.ZZ100.0789” (the data storage apparatus 102in the figures).

Based on the hierarchy information 245, the choosing program 525displays icons (621 to 623) hierarchically (i.e., in a tree view) toshow the hierarchy of the above-described data storage apparatuses.

Here, a screen image is displayed to show that the two data storageapparatuses 101 and 102 are connected downward from the data storageapparatus 201. A display example is shown in FIG. 11.

When the administrator, who operates the management console 601, choosesan icon, his instruction is sent to the management computer 501, and ascreen image 529 of a management program of the data storage apparatuscorresponding to the chosen icon is displayed in the display area 615 ofthe management console 601.

When an icon indicating a data storage apparatus of the lower level isselected in the screen image 620, then, the choosing program 525displays a screen image 625 indicating warning on the management console601, before displaying the screen image 529 of the management program.

As a result, it is possible to show the administrator operating themanagement console 601 that the object of the operation instruction is amanagement program of a lower data storage apparatus and the operationwill affect the upper data storage apparatus. In the following, will bedescribed detailed configurations for realizing the above-describedfunctions, centering on new configurations.

Hereinbelow, a first embodiment of the present invention will bedescribed referring to the drawings.

<System Configuration>

FIG. 2 shows the computer system of the present embodiment.

The computer system of the present embodiment comprises the computers301, 302, 303 and 304, the data storage apparatuses 101, 102 and 201,the management computer 501, the management console 601, and fibrechannel switches (hereinafter, referred to as FC switches) 401 and 402connecting between the computers 301 to 304 and the data storageapparatuses 101, 102 and 201.

The computers 301 to 303 are connected to the data storage apparatus 201through the FC switch 401. Further, the computer 304 is connected to thedata storage apparatus 102 through the FC switch 402.

The computers 301 to 304 each comprise a CPU 310, a memory 320 and afibre channel interface (hereinafter, referred to as an FC interface)330. The memory 320 holds programs to be executed by the CPU 310, dataread from a data storage apparatus, and data to be written to a datastorage apparatus. The computers 301 to 304 are connected to the FCswitch 401 or 402 through the FC interface 330.

The data storage apparatus 201 has three FC interfaces 230 each forconnecting with the FC switch 401. The number of the provided FCinterfaces 230 corresponds to the number of computers connected throughthe FC switch 401. The data storage apparatus 201 has a read/writeprocessing module 232 for receiving a read/write request from a computerthrough an FC interface 230, returning the requested data in thecorresponding storage area, and writing received data into a storagearea.

The data storage apparatus 201 has storage areas 211 and 212 for holdingdata used by computers. In the present embodiment, it is assumed thateach storage area has a capacity of 100 GB. Further, the data storageapparatus 201 has two FC interfaces 235 for connecting with other datastorage apparatuses. The number of the provided FC interfaces 235corresponds to the number of the other data storage apparatusesconnected.

Further, between the storage area 212 and an FC interface 235, there isprovided a synchronous control module 238 for synchronizing data betweenthe storage area 212 and the storage area 111 connected through the FCinterface 235. Control by the synchronous control module 238 isperformed such that data of two storage areas (the storage areas 111 and212, in the present embodiment) always coincide with each other.

The data storage apparatus 201 is connected with two data storageapparatuses 101 and 102 through the FC switch 402.

The data storage apparatuses 101 and 102 are each comprise an FCinterface 130 to connect with the FC switch 402, and a read/writeprocessing module 132.

The data storage apparatus 101 has the storage area 111 for holding dataused by the data storage apparatus 201. Further, the data storageapparatus 102 has the storage area 161 for holding data used by the datastorage apparatus 201 and the storage area 162 for holding data used bythe computer 304.

Each of the data storage apparatuses 101, 102 and 201 comprises: amanagement interface 220, 120 or 170 for connecting with a managementnetwork 410; a CPU 221, 121 or 171 for controlling modules and themanagement interface within the data storage apparatus 101, 102 or 201;and a memory 223 for holding programs to be executed by the CPU 221, 121or 171 and data sent and received to and from the management interface220, 120 or 170. The data storage apparatuses 101, 102 and 201 are eachconnected to the management computer 501 through the management network410.

The management computer comprises: a network interface 510 forconnecting with the management network 410; a CPU 511 for performingprocessing within the management computer 501; a memory 513 for holdingprograms to be executed by the CPU 511, data sent and received by thenetwork interface 510, and screen images to be displayed on themanagement console 601; and a network interface 590 for connecting withthe management console 601.

Using the below-mentioned management programs on the management computer501, the administrator can manage configurations and statuses of thedata storage apparatuses 201, 101 and 102. Further, through themanagement programs, the administrator can request the data storageapparatuses 101, 102 and 201 to generate or delete a storage area.

The management console 601 has the display unit 610 for displayingscreen data sent from the management computer 501. The display unit 610has display at least a window, such as display areas 611, 615 and 619.

FIG. 3 shows programs and data held by the memory 223 of the datastorage apparatus 201. The memory 223 of the data storage apparatus 201stores: a storage area information collecting request processing program225 for processing a storage area information collecting request; ahierarchy information collecting request processing program 226 forprocessing a hierarchy information collecting request; a status changenotification program 227 for notifying a change in the status of thedata storage apparatus concerned; storage area information 248;hierarchy information 245; and a notification destination holding table242.

Further, FIG. 4A shows programs and data stored in the memory 123 of thedata storage apparatus 101, and FIG. 4B shows programs and data storedin the memory 173 of the data storage apparatus 102.

The memory 123 of the data storage apparatus 101 holds: a storage areainformation collecting request processing program 125 for processing astorage area information collecting request; a status changenotification program 127 for notifying a change in the status of thedata storage apparatus concerned; storage area information 148; and anotification destination holding table 142.

The memory 173 of the data storage apparatus 102 holds: a storage areainformation collecting request processing program 175 for processing astorage area information collecting request; a status changenotification program 177 for notifying a change in the status of thedata storage apparatus concerned; storage area information 198; and anotification destination holding table 192.

FIG. 5 shows data and programs held in the memory 513 of the managementcomputer 501.

The memory 513 of the management computer 501 stores: a storage areainformation collecting program 520 for issuing a storage areainformation collecting request to a data storage apparatus; a hierarchyinformation collecting program 540 for issuing a hierarchy informationcollecting request; management programs 521 to 523 for managing the datastorage apparatuses; a choosing program 525 for making choice ofmanagement programs based on the hierarchy information; an operationwarning program 526 for notifying a warning when a specific operation isperformed; a notification destination setting program 527 for setting acomputer to which a notification from a data storage apparatus is to besent; a notification modification program 528 for modifying informationsent from a data storage apparatus, based on the hierarchy information;a management relation information creation program 550; identifierformat information 650; and management relation information 570.

As described below, the management programs 521-523 are prepared in thenumber corresponding to the number of data storage apparatuses detectedby the management computer 501. In the present embodiment, threemanagement programs are prepared since there are three data storageapparatuses.

Various programs held in the memories 223, 123 and 173 of the datastorage apparatuses 101, 102 and 201 are stored in nonvolatile storagemedia such as magnetic disk units provided in the data storageapparatuses, and, at the times of starting the data storage apparatuses,loaded onto the memories 223, 123 and 173, to be executed, respectively.The media for storing the programs may be other storage media (such asnonvolatile memories, CD-ROMs, or floppy disks) than the magnetic diskunits. Further, the programs may be loaded from the storage media inquestion onto the data storage apparatuses, to be executed. Or, thestorage media in question may be accessed through a network, to load theprograms.

Further, various programs stored in the memory 513 of the managementcomputer 501 is stored in a nonvolatile storage medium such as amagnetic disk unit provided in the management computer 501, and, at thetime of starting the management computer 501, loaded onto the memory513, to be executed. Further, the medium for storing the programs may beanother storage medium (such as a CD-ROM or a floppy disk) than themagnetic disk unit. Further, the programs may be loaded from the storagemedium in question onto the management computer, to be executed. Or, thestorage medium in question may be accessed through a network, to loadthe programs.

The present embodiment is described taking an example where fibrechannel networks are used to connect between the computers and the datastorage apparatuses, and between the data storage apparatusesthemselves. However, the kind of the networks is not limited to this.Other networks can be employed similarly, selecting devices suitable forthe employed networks, instead of the FC switches and the FC interfaces.Further, it is possible to employ a configuration where the FC switches401 and 402 are cascaded through a network 409.

Next, will be described data held in the data storage apparatuses 201,101 and 102 and the management computer 501.

<Identifier Format Information>

In the present embodiment, to specify and manage the data storageapparatuses 201, 101 and 102 and the storage areas 211, 212, 111, 161and 162 provided by those data storage apparatuses, the data storageareas are given with respective identifiers. An identifier is givenaccording to a specific format. The identifier format information 650 isdata indicating a format of an identifier to be given, namely,indicating a meaning of each component of an identifier.

FIG. 6 shows an example of the identifier format information 650 used inthe present embodiment.

As shown in the figure, it is assumed that, in the computer system ofthe present embodiment, a specific character string is used asidentification format information 650. In detail, identification formatinformation 650 is a character string in which a vendor name 651, anapparatus name 652, a manufacturer's serial number 653 and a storagearea number 654 are arranged in this order, being separated by adelimiter (a dot “.”). Each data storage apparatus 201, 101 or 102 isspecified by the vendor name 651, the apparatus name 652 and themanufacturer's serial number 653.

In the present embodiment, it is assumed that the data storage apparatus201 has a vendor name “ABC”, an apparatus name “XX200” and amanufacturer's serial number “0123”. The data storage apparatus 101 hasa vendor name “DEF”, an apparatus name “YY100” and a manufacturer'sserial number “0456”. Further, the data storage apparatus 102 has avendor name “GHI”, an apparatus name “ZZ100” and a manufacturer's serialnumber “0789”.

Further, in the present embodiment, as the storage area number 654, thenumber given to each storage area in FIG. 2 is used, for example. Inthat case, a character string becomes, for example,“ABC.XX200.0123.211”.

In the present embodiment, the management computer 501 holds theidentifier format information 650, and analyzes an identifier obtainedfrom each data storage apparatus 201, 101 or 102, according to thebelow-mentioned storage area information collecting program 520, tospecify the data storage apparatus and the storage area.

In the present embodiment, previously-given information for identifyingeach storage area may be used, as it is, as the identifier format.However, in the case where identifier formats are not consistent, or, inother words, configurations of identifiers are different from oneanother, then, it becomes impossible to match storage area informationacquired from each data storage apparatus with the hierarchyinformation. Thus, in the case where formats of previously-giveninformation do not satisfy the above condition, it is necessary in themanagement computer 501 to prepare a format conversion program thatconverts storage area identification information acquired from each datastorage apparatus 101, 102 or 201 into a format that can be matched withthe hierarchy information of the present embodiment.

<Storage Area Information>

Now, will be described storage area information 248, 148 or 198 held bya data storage apparatus 101, 102 or 201, as information on storagearea(s) 211 and 212, 111, or 161 and 162 provided by that data storageapparatus 101, 102 or 201 to a computer or the like. In the presentembodiment, the data storage apparatus 201 has the storage areainformation 248, the data storage apparatus 101 has the storage areainformation 148, and the data storage apparatus 102 has the storage areainformation 198.

FIGS. 7A, 7B and 7C are diagrams for explaining respective examples ofthe storage area information 248, the storage area information 148 andthe storage area information 198, in the present embodiment.

As shown in the figure, the storage area information 248 comprises: astorage area number 248 a, i.e., the number of storage areas provided tothe data storage apparatus 201; an identification number 248 b of themanagement interface of the data storage apparatus 201; identifiers 248c for respectively specifying the storage areas; and respectivecapacities 248 d of the storage areas. Similarly, each of the storagearea information 148 and 198 comprises the following items, namely: astorage area number 148 a or 198 a; an identification number 148 b or198 b; identifier(s) 148 c or 198 c; and capacity(-ties) 148 d or 198 d.

Here, each of the identifiers 248 c, 148 c and 198 c for specifying datastorage areas is given, being composed according to the format explainedin the above description of the identifier format information 650.

Each of the data storage apparatuses 101, 102 and 201 returns thestorage area information 248, 148 or 198 held in itself, in response toa hierarchy information collecting request sent from the managementcomputer 501.

<Hierarchy Information>

In the present embodiment, a data storage apparatus that is providedwith a storage area having another storage area in the lower level hashierarchy information. The hierarchy information stores information suchas: existence of a lower storage area, information for specifying thelower storage area when there exists such a storage area, informationindicating a data storing method, and the like. In the presentembodiment, only the data storage apparatus 201 is a data storageapparatus that is provided with a storage area having another storagearea in the lower level. Thus, as an example, will be described thehierarchy information 245 held by the data storage apparatus 201 in itsmemory 223.

FIG. 8 shows an example of the hierarchy information 245 in the presentembodiment. As shown in the figure, the hierarchy information 245comprises: a total storage area number 245 a; identifiers 245 b forspecifying storage areas; respective capacities 245 c of the storageareas; lower storage area existence flags 245 d showing whether a lowerstorage area exists; identifiers 245 e for specifying the lower storageareas; and capacities 245 d of the lower storage areas.

Here, each of the identifiers 245 b is composed according to the formatexplained in the above description of the identifier format information650.

In the present embodiment, each of the lower storage area existenceflags 245 d can have one of three values “0”, “1” and “2”. The value “0”means that no lower storage area exists. The value “1” means that alower storage area exists, the upper and lower storage areas each holddata, and the upper and lower storage areas are subject to synchronouscontrol of the synchronous control module 238. And, the value “2” meansthat a lower storage area exists and actual data is stored in the lowerstorage area.

Namely, the hierarchy information 245 shown in FIG. 8 can be interpretedas follows.

With respect to the storage area “ABC.XX200.0123.211”, the lower storagearea existence flag 245 d is “0”, and thus, the storage area“ABC.XX200.0123.211” does not have a lower storage area.

With respect to the storage area “ABC.XX200.0123.212”, the lower storagearea existence flag 245 d is “1”, and thus, the storage area“ABC.XX200.0123.212” has a lower storage area, and the identifier 245 eshows that the lower storage area in question is “DEF.YY100.0456.111”.Further, the storage area 212 and the storage area 111 are subject tosynchronous control of the synchronous control module 238.

Further, with respect to the storage area “ABC.XX200.0123.213”, thelower storage area existence flag 245 d is “2”, and thus, the storagearea “ABC.XX200.0123.213” has the lower storage area“GHI.ZZ100.0789.161”, and data is stored in the storage area 161 whilethe storage area 213 does not hold data actually. The data storageapparatus 201 can not hold data, and the storage area 161 undertakes tohold data. For example, when the data storage apparatus 201 receivesdata and an instruction from the computer 303 to write the data into thestorage area 213, then, the data storage apparatus 201 requests the datastorage apparatus 102 to write the received data into the storage area161 of the data storage apparatus 102. And, the data storage apparatus102 holds the data in the storage area 161. On the other hand, when thedata storage apparatus 201 receives a request from the computer 303 toread data from the storage area 213, then, the data storage apparatus201 reads the data from the storage area 161 that holds the data, andsends the acquired data to the computer 303.

Namely, FIG. 1 shows the storage area 213 as a virtual area, while thestorage area 213 is not actually formed on the data storage apparatus201. Thus, FIG. 2 does not show the storage area 213. The storage area161 formed in the data storage apparatus 102 is seen from the computer303 as if the storage area 161 is virtually formed in the data storageapparatus 201.

According to a hierarchy information collecting information from themanagement computer 501, the data storage apparatus 201 returns thehierarchy information 245. In the present embodiment, only the datastorage apparatus 201 has the hierarchy information collecting requestprocessing program 226, and can return the hierarchy information inresponse to a request from the management computer 501. Receiving thereturn of the hierarchy information 245, the management computer 501 canrecognize that the data storage apparatuses 101 and 102 are connectedunder the data storage apparatus 201.

<Management Relation Information>

The management relation information 570 is information generated in themanagement computer 501, from the storage area information 248, 148 and198 and the hierarchy information 245, by means of the managementrelation information creation program 550. The management relationinformation 570 stores information on the hierarchical configuration ofthe data storage apparatuses 201, 101 and 102, information required forthe management computer 501 to access the data storage apparatuses, andthe like. Here, the information on the hierarchical configuration isgenerated based on the hierarchy information on the storage areas.

FIG. 9 shows an example of the management relation information 570. Asshown in the figure, the management relation information 570 comprises:an upper data storage apparatus storage part 5701 for storinginformation on an upper data storage apparatus; and a lower data storageapparatus storage part 5702 for storing information on lower datastorage apparatuses having lower storage areas connected hierarchicallyto storage areas provided by the upper data storage apparatus.

Further, the upper data storage apparatus storage part 5701 comprises: adata storage apparatus number 5701 a for specifying the data storageapparatus; a management interface identification number 5701 b forspecifying the management interface of the data storage apparatus inquestion; a management program identification number 5701 c forspecifying a management program provided in the management computer 501for each data storage apparatus; an icon number 5701 d; and anidentifier 5701 d.

The lower data storage apparatus storage part 5702 comprises: datastorage apparatus numbers 5702 a; management interface identificationnumbers 5702 b; management program identification numbers 5702 c; iconnumbers 5702 d; and identifiers 5702 e.

When the management computer 501 receives the hierarchy information 245,then, from the identifier 245 b, the management computer 501 extractsthe identifier specifying the upper data storage apparatus, and storesthe extracted identifier as the identifier 5701 e of the upper datastorage apparatus 5701. Further, from the identifiers 245 e, themanagement computer 501 extracts all the identifiers that are stored inthe identifiers 245 e and specify the lower data storage apparatuses,and stores the extracted identifiers as the identifiers 5702 e of thelower data storage apparatuses 5702.

Next, the management computer 501 stores information specifying themanagement programs and information specifying the management interfacesas communication interfaces, into the corresponding management programidentification numbers 5701 c and 5702 c and the correspondingmanagement interface identification numbers 5701 b and 5702 b,respectively. The information specifying the management programs and theinformation specifying the management interfaces can be determined whenthe management computer 501 acquires the storage area information 248,148 and 198 of the data storage apparatuses 201, 101 and 102, by meansof the below-mentioned storage area information collecting program 520.

Here, the data storage apparatus numbers are numbers that are given forthe sake of convenience for identifying the data storage apparatusesspecified by the identifiers, respectively. In the present embodiment,the numbers used in FIG. 2 for specifying the data storage apparatusesare used as the data storage apparatus numbers. Namely, in the case ofthe data storage apparatus 201 that is specified by the identifier 5701e “ABC.XX200.0123”, “201” is stored as the data storage apparatusnumber. In the cases of the data storage apparatuses 101 and 102, whichare specified by their identifiers 5702 e, “GHI.ZZ100.0789” and“DEF.YY100.0456”, “101” and “102” are stored as the respective datastorage apparatus numbers.

Further, the icon numbers 5701 d and 5702 d are given when thebelow-mentioned choosing program 5525 generates the screen image 620.

<Processing in the Management Computer 501>

Next, referring to a flowchart of FIG. 10, will be described processingperformed in the management computer 501 in the case where storage areashave hierarchy, in the computer system of the present embodiment.

[Step 1601]

The CPU 511 of the management computer 501 executes the storage areainformation collecting program 520 to issue storage area informationcollecting requests through the network interface 510 to all the storagearea connected to the management network 410, trying to collect thestorage area information 248, 148 and 198 from the data storageapparatuses 210, 101 and 102.

Receiving respective storage area information collecting requests fromthe management computer 501, the data storage apparatuses 210, 101 and102 execute the storage area information collecting request processingprograms 225, 125 and 175 to return the storage area information 248,148 and 198 to the management computer 501, respectively.

From the storage area information 248, 148 and 198 collected by means ofthe storage area information collecting program 520, the CPU 511recognizes that the data storage apparatuses 210, 101 and 102 areconnected to the management network 410.

In the present embodiment, it is possible to collect the storage areainformation 248, 148 and 198 shown in FIG. 7 from the three data storageapparatuses 201, 101 and 102. By means of the storage area informationcollecting program 520, the CPU 511 compares identifiers 248 c, 148 cand 198 c included in the collected storage area information 248, 148and 198 with the identifier format information 650, to acquire thevendor names, the apparatus names and the manufacturer's serial numbersof the data storage apparatuses 210, 101 and 102. And, based on theacquired information, the CPU 511 can identify the data storageapparatuses 201, 101 and 102 connected to the management network 410.

[Step 1605]

By means of the storage area information collecting program 520, the CPU511 of the management computer 501 prepares management programs, thenumber of which corresponds to the storage area information that can becollected in the above-described step. In the present embodiment, threepieces of data area information can be collected in the above-describedstep. Accordingly, by means of the storage area information collectingprogram 520, the CPU 511 recognizes that three data storage apparatusesare connected, and prepares three management programs (521-523) in thememory 513.

In the present embodiment, the management programs corresponding to thedata storage apparatuses have been loaded onto the memory 513 inadvance. And, here, those programs are activated such that the choosingprogram 525 can be executed.

[Step 1609]

Then, by means of the storage area information collecting program 520,the CPU 511 of the management computer 501 sets the management interfaceidentification numbers 248 b, 148 b and 198 b included respectively inthe storage area information 248, 148 and 198, into the communicationchoosing modules provided in the management programs 521, 522 and 523.

Here, each of the communication choosing modules is a module forspecifying the identification number of the interface that themanagement program concerned can communicate with. In the presentembodiment, the management programs 521, 522 and 523 are each preparedsuch that the management program in question can communicate with themanagement interface having the identification number set in thecommunication choosing module.

In the present embodiment, “220” is set into the communication choosingmodule of the management program 521, “120” into the communicationchoosing module of the management program 522, and “170” into thecommunication choosing module of the management program 523. Thus, inthe present embodiment, as the management interface identificationnumbers 248 b, 148 b and 198 b held in the storage area information 248,148 and 198, the numbers shown in FIGS. 7A, 7B and 7C are given,respectively. However, IP addresses given in advance to the managementinterfaces may be set into the communication choosing modules,respectively. Through the management interfaces 220, 120 and 170, themanagement program 521 can communicate with the data storage apparatus201 only, the management program 522 with the data storage apparatus 101only, and the management program 523 with the data storage apparatus 102only.

[Step 1613]

Next, the CPU 511 of the management computer 501 executes the hierarchyinformation collecting program 540 to issue hierarchy informationcollecting requests through the network interface 510 to all the datastorage apparatuses 201, 101 and 102 connected to the management network410, trying to collect the hierarchy information from the data storageapparatuses 201, 101 and 102.

In the present embodiment, only the data storage apparatus 201 has lowerstorage areas, and accordingly, has the hierarchy information collectingrequest processing program 226.

Among the data storage apparatuses 201, 101 and 102 that have receivedthe hierarchy information collecting requests, only the data storageapparatus 201 holds the hierarchy information 245 and can return thehierarchy information 245. The CPU 221 of the data storage apparatus 201executes the hierarchy information collecting request processing program226 to return the hierarchy information 245 to the management computer501. In the present embodiment, the management computer 501 can acquirethe hierarchy information 245 shown in FIG. 8.

[Step 1617]

By means of the hierarchy information collecting program 540, the CPU511 of the management computer 501 recognizes that the data storageapparatuses 101 and 102 are connected under the data storage apparatus201, based on the identifiers 245 b, the lower storage area existenceflags 245 d and the identifiers 245 e included in the acquired hierarchyinformation 245. Then, by means of the management relation informationcreation program 550, the CPU 511 of the management computer 501 createsthe management relation information 570 from the acquired storage areainformation 248, 148 and 198 and the acquired hierarchy information 245.

[Step 1621]

The CPU 511 of the management computer 501 executes the choosing program525. The choosing program 525 refers to the management relationinformation 570 to create a screen image 620 to be displayed on themanagement console 601. By means of the choosing program 525, the CPU511 sends the created screen image 620 to the management console 601through the network interface 590.

Receiving the screen image 620 from the choosing program 525, themanagement console 601 displays the screen image 620 in the display area611 of the display unit 610.

FIG. 11 shows an example of the screen image in the present embodiment.The screen image 620 includes an icon 621 indicating the data storageapparatus 201, an icon 622 indicating the data storage apparatus 101,and an icon 623 indicating the data storage apparatus 102. Those iconsare displayed in a tree view using line segments 629 expressing thehierarchy, according to the hierarchy recognized from the managementrelation information 570. Further, in the respective neighborhoods ofthe icons 621, 622 and 623 indicating the data storage apparatuses 201,101 and 102, there are provided display areas 631-633 each displayingthe vendor name, the apparatus name and the manufacturer's serialnumber.

[Step 1625]

At that time, the choosing program 525 stores the respectiveidentification numbers of the icons 621, 622 and 623 (which aredisplayed on the display unit 610 and indicate respectively the datastorage apparatuses 201, 101 and 102) into the management relationinformation 570. As a result, when the management computer 501 receivesan administrator's designation that chooses a certain icon, then, themanagement computer 501 can recognize the designated data storageapparatus from the management relation information 570. In the presentembodiment, the respective numbers “621”, “622” and “623” of the iconsshown in FIG. 11 are held in the management relation information 570.

[Step 1629]

The administrator who uses the management console 601 can use a mouse(not shown) provided to the management console 601 to operate a mousecursor 699 on the display unit 610.

Receiving the choice by the administrator, the management console 601sends the identification number of the chosen icon to the managementcomputer 501 through the network interface 590.

In the present embodiment, as shown in FIG. 11, three icons 621-622 areshown in the screen image 620 displayed in the display area 611. Movingthe mouse cursor 699 on the display unit 610, and pushing a mouse'sbutton when the cursor 699 is at the desired icon, the administrator canchoose a target data storage apparatus. The input device of themanagement console 601 is not limited to the mouse, and, for example, akeyboard may be used.

[Step 1633]

Next, by means of the choosing program 525, the CPU 511 of themanagement computer 501 judges the data storage apparatus chosen by theadministrator through the mouse. Here, it is judged whether a lower datastorage apparatus (i.e., a data storage apparatus under another datastorage apparatus) has been chosen or not.

When the chosen data storage apparatus is a data storage apparatus underanother data storage apparatus, the processing flow proceeds to thebelow-described step 1637, and otherwise, the processing flow proceedsto the below-described step 1645.

In the present embodiment, the CPU 511 of the management computer 501generates the management relation information 570 based on the hierarchyinformation 245, and uses the management relation information 570 tomake up the screen image 620 by means of the choosing program 525. As aresult, the hierarchy in the screen image 620 displayed on themanagement console 601 coincides with the hierarchy of the data storageapparatuses 201, 101 and 102. Thus, when the icon 622 or 623 is chosenon the screen image 620 displayed on the display unit 610 of themanagement console 601, then, by means of the choosing program 525, theCPU 511 of the management computer 501 can judge from the managementrelation information 570 that the data storage apparatus 101 or 102under the data storage apparatus 201 has been chosen.

[Step 1637]

Receiving the identification number of the chosen icon, the CPU 511 ofthe management computer 501 refers to the management relationinformation 570. When, by means of the choosing program 525, the CPU 511recognizes from the management relation information 570 that the datastorage apparatus corresponding to the identification number 5701 d or5702 d of the chosen icon is under another data storage apparatus, then,the CPU 511 executes the operation warning program 526 to generate ascreen image 640 indicating that operation on the chosen data storageapparatus will affect the upper data storage apparatus and to send thegenerated screen image 640 to the management console 601.

The management console 601 displays the received screen image 640 in adisplay area 641. FIG. 12 shows an example in which the screen image 620and the screen image 640 are displayed on the management console.

As shown in the figure, the screen image 640 comprises a warning messagedisplay area 641 and an OK button for receiving an instruction ofconfirmation from the administrator.

[Step 1641]

When the administrator confirms the warning on the display unit 610 ofthe management console 601, the administrator pushes the confirmationbutton 649 using the mouse cursor 699. Receiving the push of theconfirmation button 649, the management console 601 notifies the CPU 511of the management computer 501 to that effect.

[Step 1645]

When the CPU 511 of the management computer 501 receives theidentification number 621, 622 or 623 of the chosen icon, then, by meansof the choosing program 525, the CPU 511 refers to the managementrelation information 570 to acquire the management program number 5701 cor 5702 c corresponding to the received identification number 5701 d or5702 d of the icon. Then, the CPU 511 instructs the management programof the acquired number 521, 522 or 523 to send the management console601 a screen image for managing the data storage apparatus in question.Here, the screen image send by the management program in question is aconfiguration display screen, a status display screen, a setting inputscreen, or the like used for managing the data storage apparatus.

[Step 1649]

Receiving the screen image from the management program 521, 522 or 523,the management console 601 displays the received screen image in thedisplay area 615 on the display unit 610.

In the present embodiment, according to the above-described processingby the management computer 501, as the screen image 620, the hierarchyof the data storage apparatuses is displayed in the display area 611 onthe display unit 610 of the management console 601, and the managementinformation of the data storage apparatus designated by theadministrator is displayed in the display area 615 on the display unit610.

When the administrator chooses a data storage apparatus, which theadministrator wishes to manage, through the screen image 620 generatedby the choosing program 525, the administrator can display themanagement program for managing the target data storage apparatus on themanagement console, to confirm the configuration or the status, or toperform setting of the data storage apparatus. At that time, it ispossible at the same time to confirm the data storage apparatuses'hierarchy information that can not be recognized from the computers301-304, and this reduces, for example, the risk of deleting a storagearea used by an upper data storage apparatus without being conscious ofthe hierarchy.

<Notification Processing of a Data Storage Apparatus>

Next, will be described notification processing of a data storageapparatus 201, 101 or 102. The notification processing of a data storageapparatus 201, 101 or 102 means processing of immediately notifying themanagement computer 501 of a change in the status of a data storageapparatus 201, 101 or 102 when the change occurs in the data storageapparatus 201, 101 or 102 owing to, for example, a failure in acomponent part of the data storage apparatus in question.

In the present embodiment, to perform the notification processing, thedata storage apparatuses 201, 101 and 102 have the notificationdestination holding tables 242, 142 and 192 and the status changenotification programs 227, 127 and 177, respectively.

The notification destination holding tables 242, 142 and 192 each holdthe network interface number 510 or 590 of the management computer 501for sending a notification when a change occurs in the status of thedata storage apparatus 201, 101 or 102 concerned. When a status changeoccurs, the status change notification program 227, 127 or 177 notifiesinformation indicating the kind of the status change, as status changenotification information 900, to the network interface 510 or 590.

FIG. 13 shows the status change notification information 900 in thepresent embodiment. As shown in the figure, the status changenotification information 900 comprises a management interface numberholding area 901 for holding the management interface number of thenotification source, and a message holding area 902 for holding amessage.

The management interface number holding area 901 stores the managementinterface number of the data storage apparatus that has issued themessage. In the present embodiment, the number shown in FIG. 2 isstored. Further, the message holding area 902 stores a messageexpressing a status, such as “a magnetic disk unit of the data storageapparatus 101 has filed”, for example.

In the following, the notification processing of a data storageapparatus will be described referring to a flowchart of FIG. 14.

[Step 1701]

For immediately recognizing a change in the statuses of the data storageapparatuses 201, 101 and 102, the CPU 511 of the management computer 501executes the notification destination setting program 527 to set anetwork interface number of the management computer 501 to thenotification destination holding tables 242, 142 and 192 of all the datastorage apparatuses 201, 101 and 102 connected to the managementcomputer 501. The network interface number of the management computer501 is used for receiving a status change notification. Here, forexample, “510” is set as the network interface number of the managementcomputer 501.

[Step 1705]

As a result, the management computer 501 can receive a notification whena change occurs in the status of a data storage apparatus. In thisstate, the management computer 501 awaits a notification.

[Step 1709]

In the present embodiment, the management computer 501 is provided withnotification modification program 528. The notification modificationprogram 528 refers to the management relation information 570 tocorrectly recognize the hierarchy of the data storage apparatuses in thecomputer system.

The CPU 511 of the management computer 501 executes the notificationmodification program 528 to refer to the management interface numberholding area 901 of status change notification information 900 receivedthrough the network interface 510, in order to recognize which datastorage apparatus has sent the notification. Then, by means of thenotification modification program 528, the CPU 511 modifies the contentsof the received message into a message reflecting the hierarchy.

In detail, when status change notification information including amessage “a magnetic disk unit of the data storage apparatus 101 hasfailed” is received, then, by means of the notification modificationprogram 528, the CPU 511 refers to the management relation information570 to recognize that the data storage apparatus 101 is under the datastorage apparatus 201, and modifies the message into a message “amagnetic disk unit of the data storage apparatus 101 under the datastorage apparatus 201 has failed”.

[Step 1713]

By means of the notification modification program 528, the CPU 511 sendsthe status change notification information 900 including the modifiedmessage to the management console 601.

[Step 1717]

The management console 601 prepares the display area 619 on the displayunit 610, to display the received message.

In the present embodiment, according to the above-described processing,it is possible to modify status change notification information 900received from a data storage apparatus into status change notificationinformation 900 reflecting the hierarchical configuration of the datastorage apparatuses, and to display the modified status changenotification information 900 on the management console 601.

According to thus-described arrangement of the present embodiment, theadministrator can acquire information reflecting the hierarchy even whenthe status of the data storage apparatuses is changed, and thus, canjudge correctly at processing operation performed thereafter.

The above-described embodiment has been described taking the examplewhere only a data storage apparatus having a lower data storageapparatus is provided with the hierarchy information 245. However, aform of holding the hierarchy information 245 is not limited to this.For example, the lower data storage apparatuses may hold the hierarchyinformation 245 also.

In the case where the lower data storage apparatuses hold the hierarchyinformation 245 also, the management computer 501 refers to the lowerstorage area existence flags 245 d out of the hierarchy information 245acquired from a lower data storage apparatus, to judge whether thereexists a lower data storage apparatus. Namely, the flags 245 d show thevalue “0”, then it is judged that no lower data storage apparatusexists.

Further, the above embodiment has been described taking the examplewhere the respective management programs are prepared correspondingly tothe data storage apparatuses. However, the present invention is notlimited to this. For example, one management program may accommodate aplurality of data storage apparatuses, and manage identification numbersof the management interfaces of that plurality of data storageapparatuses, so that the management computer can communicate with anindividual data storage apparatus. In that case, it is not necessary toactivate management programs, the number of which is same as the numberof the data storage apparatuses, and it is sufficient to activate amanagement program or programs corresponding to a plurality of datastorage apparatuses detected.

[Second Embodiment]

Now, a second embodiment of the present invention will be describedreferring to drawings.

<Outline>

A second embodiment further comprises management computer 5011 and 5012as management computers for respectively managing the data storageapparatuses 101 and 102. The management computer 501 manages the datastorage apparatuses 201, 101 and 102 similarly to the first embodiment.However, the data storage apparatuses 101 and 102 are connected to themanagement computer 501 through the management computers 5011 and 5012,respectively. The management computer 501 manages the data storageapparatuses 101 and 102 through the management computers 5011 and 5012,respectively.

In the present embodiment, the management computer 501 directly managesthe data storage apparatus 201 by means of a management program 521 tobe executed in the management computer 501. However, the data storageapparatuses 101 and 102 are managed by means of management programs 522and 523 to be executed in the management computers 5011 and 5012,respectively.

In the following, will be described a management system of data storageapparatuses in a computer system having a plurality ofhierarchically-connected data storage apparatuses, in the case of thepresent embodiment where the data storage apparatuses are connected withthe respective management computers 5011 and 5012. In the description ofthe present embodiment, the same numerals indicate components having thesame functions or configurations as in the first embodiment, and detailsof those components are not described.

<System Configuration>

FIG. 15 shows a computer system of the second embodiment.

As shown in the figure, the computer system of the present embodimentfurther comprises the management computer 5011 between the data storageapparatus 101 and the management network 410 and the management computer5012 between the data storage apparatus 102 and the management network410, in addition to the components of the computer system of the firstembodiment.

Each of the management computers 5011 and 5012 is connected to the datastorage apparatus 101 or 102 and the management computer 410 throughrespective network interfaces 5101 or 5102 and 5901 or 5902.

FIG. 16 shows programs and data held in the memory 513 of the managementcomputer 501 of the present embodiment. Further, FIGS. 17, 18A and 18Bshow programs and data held in the memories 223, 123 and 173 of the datastorage apparatuses 210, 101 and 102, respectively.

The memory 223 of the data storage apparatus 201 stores, in addition tothe data and programs held in the case of the first embodiment:management computer identification information 243 for holdingidentification information used for identifying a management computerthat manages the data storage apparatus 201 now; and management computeridentification information collecting request processing program 228 forprocessing a management computer identification information collectingrequest from a management computer.

Further, the memory 123 of the data storage apparatus 101 stores, inaddition to the data and programs held in the case of the firstembodiment: management computer identification information 143 forholding identification information used for identifying a managementcomputer that manages the data storage apparatus 101 now; and amanagement computer identification information collecting requestprocessing program 128 for processing a management computeridentification information collecting request from a managementcomputer. And, the memory 173 of the data storage apparatus 102 stores,in addition to the data and programs held in the case of the firstembodiment: management computer identification information 193 forholding identification information used for identifying a managementcomputer that manages the data storage apparatus 102 now; and amanagement computer identification information collecting requestprocessing program 178 for processing a management computeridentification information collecting request from a managementcomputer.

The memory 513 of the management computer 501 stores, in addition to thedata and programs held in the case of the first embodiment: a managementcomputer identification information collecting program 529 forcollecting management computer identification information from themanagement computer identification information held by a data storageapparatus, in order to recognize which management computer manages thedata storage apparatus at present; and a management computeridentification information setting program 530 for settingidentification information of a management computer connected to a datastorage apparatus.

<Format of Management Computer Identification Information>

As shown in FIGS. 19A-19C, the management computer identificationinformation 243, 143 and 193 each comprise: a first network interfacenumber holding area 243 a, 143 a or 193 a for holding an identificationnumber of a network interface of the management computer 501, 5011 or5012 connected to the data storage apparatus 201, 101 or 102; a secondnetwork interface number holding area 243 b, 143 b or 193 b for holdingan identification number of a network for the management computer 501,5011 or 5012 to communicate with another management computer; and amanagement program number holding area 243 c, 143 c or 193 c for holdingan identification number of the management program held by themanagement computer in question.

Here, in the case where a data storage apparatus does not use amanagement computer, “0” is stored into the first network interfacenumber holding area 243 a, 143 a or 193 a and into the second networkinterface number holding area 243 b, 143 b or 193 b. In that case, thereis not a management program either, and “0” is stored into themanagement program number holding area 243 c, 143 c or 193 c also.

For example, in FIG. 19A, both the first network interface numberholding area 243 a and the second network interface number holding area243 b store “0”. This means that the data storage apparatus 201 havingthe management computer identification information 243 has no managementcomputer in use.

<Prerequisites for the Management Programs of the Data StorageApparatuses 101 and 102>

In the present embodiment, in the management computer 5011, an unshownmemory stores the management program 522 for managing the data storageapparatus 101, and an unshown CPU executes the management program 522.Further, in the management computer 5012, an unshown memory stores themanagement program 523 for managing the data storage apparatus 102, andan unshown CPU executes the management program 523.

Thus, in the present embodiment, the data storage apparatus 101 ismanaged by the management computer 5011, and the data storage apparatus102 is managed by the management computer 5012.

As shown in FIG. 19B, the management computer identification information143 held in the memory 123 of the data storage apparatus 101 stores: asthe first network interface number 143 a, the network interface 5101 forthe management computer 5011 to connect to the data storage apparatus101; as the second network interface number 143 b, the network interface5901 for the management computer 5011 to connect to the managementcomputer 501 through the management network 410.

Similarly, as shown in FIG. 19C, the management computer identificationinformation 193 held in the memory 173 of the data storage apparatus 102stores the first network interface number 193 a and the second networkinterface number 193 b.

<Processing by the Management Computer 501>

Next, processing by the management computer 501 in the presentembodiment will be described referring to a flowchart of FIG. 20.

[Step 1801]

The CPU 511 of the management computer 501 executes the storage areainformation collecting program 520 to issue storage area informationcollecting requests through the network interface 510 to all the datastorage apparatuses connected to the management network 410, trying tocollect the storage area information 248, 148 and 198 from the datastorage apparatuses 201, 101 and 102, respectively.

Receiving a storage area information collecting request from themanagement computer 501, each CPU 221, 121 or 171 of the data storageapparatuses 210, 101 and 102 executes the storage area informationcollecting request processing program 225, 125 or 175 to return thestorage area information 248, 148 or 198 to the management computer 501.By means of the storage area information collecting program 520, andbased on the collected storage area information 248, 148 and 198, theCPU 511 of the management computer 501 recognizes that the data storageapparatuses 210, 101 and 102 are connected to the management network410.

In the present embodiment, similarly to the first embodiment, thestorage area information 248, 148 and 198 shown in FIG. 7 can becollected from the three data storage apparatuses 201, 101 and 102.

[Step 1803]

Next, the CPU 511 of the management computer 501 executes the managementcomputer identification information collecting program 529, to issuemanagement computer identification information collecting requeststhrough the network interface 510 to all the data storage apparatusesconnected to the management network 410, trying to collect themanagement computer identification information 243, 143 and 193 from thedata storage apparatuses 210, 101 and 102, respectively.

Receiving the management computer identification information collectingrequests from the management computer 501, the CPUs 221, 121 and 171 ofthe data storage apparatuses 210, 101 and 102 execute the managementcomputer identification information collecting request processingprograms 228, 128 and 178, to return the management computeridentification information 243, 143 and 193 to the management computer501, respectively.

Collecting the management computer identification information 243, 143and 193 by means of the management computer identification informationcollecting program 529, the CPU 511 recognizes the respective managementcomputers connected to the data storage apparatuses 210, 101 and 102.

In the present embodiment, the CPU 511 acquires the management computeridentification information 243 shown in FIG. 19A from the data storageapparatus 201, the management computer identification information 143shown in FIG. 19B from the data storage apparatus 101, and themanagement computer identification information 193 shown in FIG. 19Cfrom the data storage apparatus 102.

The management computer identification information 243 acquired from thedata storage apparatus 201 stores “0” in both the first and secondnetwork interface number holding areas 243 a and 243 b, as describedabove. Thus, by means of the management computer identificationinformation collecting program 529, the CPU 511 recognizes that the datastorage apparatus 201 is not connected with a management computer atpresent.

[Step 1805]

Next, the management computer 501 judges the number of the managementprograms that are to be prepared in the management computer 501 itselffor managing data storage apparatuses. Namely, the management computer501 judges the number of data storage apparatuses that are each notconnected to a management computer at present, and thus, should bemanaged by the management computer 501 itself, and prepares a judgednumber of management programs.

In the present embodiment, by means of the storage area informationcollecting program 520 and the management computer identificationinformation collecting program 529, the CPU 511 of the managementcomputer 501 recognizes that the three data storage apparatuses 210, 101and 102 exist, from the number of the collected storage area information248, 148 and 198, and that, among the three data storage apparatuses,the two data storage apparatuses 101 and 102 already have the respectivemanagement computers 5011 and 5012. Thus, by means of the storage areainformation collecting program 520, the CPU 511 judges that the numberof data storage apparatuses to be managed by the management computer 501itself is one, or in other words, the number of management programs tobe prepared in the management computer 501 itself is one. Thus, the CPU511 prepares only one management program 521 in the memory 513.

At that time, as another method, the data storage apparatuses 101 and102 may generate a message that those data storage apparatuses 101 and102 already have the management computers 5011 and 5012, and display themessage through the management console 601. The administrator who seesthe message can perform, for example, processing of removing themanagement computers 5011 and 5012 connected to the data storageapparatuses 101 and 102. By this processing, the management computer 501can make three management programs prepared in the management computer501 to manage the three data storage apparatuses 201, 101 and 102,according to a similar configuration to the first embodiment.

[Step 1809]

Then, by means of the storage area information collecting program 520,the CPU 511 of the management computer 501 sets the management interfaceidentification number 248 b held in the storage area information 248into a communication choosing module provided in the management program521. In the present embodiment, “220” is set into the communicationchoosing module of the management program 521.

[Step 1811]

The CPU 511 of the management computer 501 executes the managementcomputer identification information setting program 530, to sendinformation to the data storage apparatuses to which the managementcomputer 501 itself has been connected. Here, the information to be sentis information indicating that the management computer 501 itself hasbeen connected to those data storage apparatuses. In other words, theinformation to be sent is the network interface identification numbersto be used for connection of the management computer 501 itself.

In the present embodiment, the network interface identification number510 and the network interface identification number 590 for connectingwith another apparatus are sent respectively as the first and secondnetwork interface identification numbers to the data storage apparatus201.

By means of the management computer identification informationcollecting request processing program 228, the CPU 221 of the datastorage apparatus 201 stores the received numbers into the managementcomputer identification information 243, to hold the numbers therein.FIG. 19D shows an example of data held in the management computeridentification information 243 in this case.

[Step 1813]

Next, the CPU 511 of the management computer 501 executes the hierarchyinformation collecting program 540 to issue hierarchy informationcollecting requests through the network interface 510 to all the datastorage apparatuses connected to the management network 410, trying tocollect the hierarchy information from the data storage apparatuses.

In the present embodiment, similarly to the first embodiment, only thedata storage apparatus 201 has lower storage areas, and accordingly, hasthe hierarchy information collecting request processing program 226. Asa result, the hierarchy information can be acquired from the datastorage apparatus 201 only.

Receiving the hierarchy information collecting request, the CPU 221 ofthe data storage apparatus 201 executes the hierarchy informationcollecting request processing program 226 to send the hierarchyinformation 245 to the management computer 501. In the presentembodiment, the management computer 501 can acquire the hierarchyinformation 245 shown in FIG. 8.

[Step 1817]

By means of the hierarchy information collecting program 540, the CPU511 of the management computer 501 recognizes that the data storageapparatuses 101 and 102 are connected under the data storage apparatus201, based on the acquired hierarchy information 245. This recognitionmethod is similar to the first embodiment. Similarly to the firstembodiment, the CPU 511 of the management computer 501 generatesmanagement relation information 580 from the collected storage areainformation 248, 148 and 198, the hierarchy information 245, and themanagement computer identification information 143 and 193.

FIG. 21 shows the management relation information 580 in the presentembodiment. The management relation information 580 is different fromthe management relation information 570 shown in FIG. 9 of the firstembodiment in that each of the upper data storage apparatus and thelower data storage apparatuses hold a management device number 5801 f or5802 f. Referring to the management relation information 580, the CPU511 of the management computer 501 can recognize, by means of eachprogram, the management computers 501, 5011 and 5012 in which themanagement programs for managing the data storage apparatuses 201, 101and 102 are executed respectively, and the respective managementprograms 521, 522 and 523.

[Step 1821]

The CPU 511 of the management computer 501 executes the choosing program525. The choosing program 525 refers to the management relationinformation 580 to generate the screen image shown in FIG. 11 similarlyto the first embodiment.

[Step 1825]

Similarly to the first embodiment, the choosing program 525 stores theicon identification numbers 621, 622 and 623 displayed on the displayunit 610 into the management relation information 580, to hold the iconidentification numbers 621, 622 and 623 therein. In the presentembodiment, the icon identification numbers “621”, “622” and “623” shownin FIG. 11 are held as the icon numbers in the management relationinformation 580, similarly to the first embodiment.

[Step 1829]

Similarly to the first embodiment, when a choice of icon is receivedfrom the administrator, the management console 601 sends theidentification number of the chosen icon to the management computer 501through the network interface 590.

[Step 1833]

By means of the choosing program 525, the CPU 511 of the managementcomputer 501 judges the data storage apparatus chosen by theadministrator through the mouse. Here, similarly to the firstembodiment, it is judged whether a lower data storage apparatus (i.e., adata storage apparatus under another data storage apparatus) has beenchosen or not.

When the chosen data storage apparatus is a data storage apparatus underanother data storage apparatus, the processing flow proceeds to thebelow-described step 1837, and otherwise, the processing flow proceedsto the below-described step 1845.

[Step 1837]

In the present embodiment also, when various programs are executed, theCPU 511 of the management computer 501 can recognize the hierarchy ofthe data storage apparatuses, by referring to the management relationinformation 580, similarly to the first embodiment.

When, by means of the choosing program 525, the CPU 511 of themanagement computer 501 recognizes that the data storage apparatuscorresponding to the received icon identification number is underanother data storage apparatus, then, similarly to the first embodiment,the CPU 511 executes the operation warning program 526 to generate thescreen image 640 indicating that operation on the chosen data storageapparatus will affect the upper data storage apparatus and to send thegenerated screen image 640 to the management console 601. Here, thescreen image 640 generated and displayed on the management console 601is similar to the first embodiment, and its details are not describedhere.

[Step 1841]

When the administrator confirms the warning on the display unit 610 ofthe management console 601, the administrator pushes the confirmationbutton 649 using the mouse cursor 699. Receiving the push of theconfirmation button 649, the management console 601 notifies the CPU 511of the management computer 501 to that effect.

[Step 1845]

When the CPU 511 of the management computer 501 receives theidentification number of the chosen icon, then, by means of the choosingprogram 525, the CPU 511 refers to the management relation information580 to acquire the management computer number and the management programnumber corresponding to the identification number of the received icon.Then, the CPU 511 instructs the management program of the managementcomputer concerned to send a screen image for managing the data storageapparatus in question to the management console 601. The screen image tobe sent is similar to the first embodiment.

Differently from the first embodiment, when the data storage apparatus101 is chosen, then, by means of the choosing program 525, the CPU 511of the management computer 501 instructs the management program 522 ofthe management computer 5011 to send the screen image to the managementconsole 601. And, when the data storage apparatus 102 is chosen, the CPU511 of the management computer 501 instructs the management program 523of the management computer 5012 to send the screen image to themanagement console.

[Step 1849]

When the management console 601 receives a screen image from themanagement program 521, 522 or 523, then, the management console 601displays the received screen image in the display area 615 on thedisplay unit 610.

As described above, even in the case of the present embodiment where themanagement computer 501 has the data storage apparatuses 101 and 102connected through the other management computers 5011 and 5012respectively, and the hierarchy of the storage areas exists, themanagement computer 501 can correctly recognize the hierarchy of thedata storage apparatuses 201, 101 and 102, and can correctly managethose data storage apparatuses. When a user tries to perform operationaffecting a plurality of hierarchy levels, it is possible to notify theuser to that effect.

Further, in the present embodiment, similarly to the first embodiment,it is possible to arrange the system such that a notification of achange in the status of a data storage apparatus can be processedaccording to the hierarchy of the data storage apparatuses. As a result,in the present embodiment also, it is possible to send a notificationconsidering the hierarchy to the administrator.

In the present and first embodiments, it may be arranged that themanagement computer 501 acquires the hierarchy of the data storageapparatuses periodically or being triggered by a change notificationfrom a data storage apparatus. Then, the management relation informationcan be updated within the management computer 501 for automaticallyrecognizing the hierarchy of the data storage apparatuses even in thecase of a change in the hierarchy of the data storage apparatuses.

According to the above-described embodiment, it is possible to provide amanagement screen through which the hierarchy of data storageapparatuses can be easily grasped in a computer system havinghierarchically-arranged data storage apparatuses, and to properly notifyeffects of administrator's operation on the configuration of the datastorage apparatuses. Further, according to the above-describedembodiments, the management computer can properly acquire informationsuch as a change in the configuration of the data storage apparatuses,and the acquired information can be presented to the administrator.

Thus, according to the above-described embodiments, it is possible toaid the administrator in the management of the data storage apparatuses.

1. A management computer connected through a second network to data storage apparatuses that are connected to computers through a first network, said management computer comprising: a storage area information collecting module which collects respective pieces of storage area information from said data storage apparatuses connected through the second network, wherein each piece of storage area information relates to storage areas provided by a data storage apparatus concerned; a hierarchy information collecting module which collects respective pieces of hierarchy information from said data storage apparatuses connected through said second network, wherein each piece of hierarchy information indicates hierarchy among data storage apparatuses held by a data storage apparatus concerned; and a management relation information creation module which sets hierarchy among said data storage apparatuses to create management relation information, based on said pieces of storage area information and said pieces of hierarchy information collected in said storage area information collecting module and said hierarchy information collecting module. 2.-20. (canceled) 